It is known to provide a single-hull displacement type water craft which is capable of moving relatively efficiently through a body of water at low speed. However, as the speed increases, it is known that craft with multiple long slender hulls (such as catamarans) provide improved efficiency. As speeds increase further it is known to provide planing-type water craft which significantly reduce the volume of water displaced when planing and therefore provide increased efficiency at high speeds. The hulls of planing water craft are generally wider (especially towards the rear) and shorter than displacement water craft.
The applicant's U.S. Pat. No. 7,314,014, details of which are incorporated herein by reference, discloses a water craft having a chassis and least four water engaging means. This prior invention is applicable to displacement and planing craft uses, providing suspension to reduce shocks to the body of the water craft, especially when travelling at speed over turbulent water. The vertical displacement of each water engaging means relative to the chassis is controlled by a suspension system providing interconnected hydraulic rams to maintain the chassis at a substantially constant height and orientation relative to the average surface of the water (as defined by the water engaging means). However as waves are encountered, the average surface of the water does not remain level, causing the body of the water craft to experience corresponding roll or pitch.
It is therefore an object of the present invention to provide an improved control of the roll and/or pitch attitude of the body of a water craft.